/*
 * Copyright 2002-2020 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.core.log;

import java.util.function.Supplier;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * A convenient accessor for Commons Logging, providing not only
 * {@code CharSequence} based log methods but also {@code Supplier}
 * based variants for use with Java 8 lambda expressions.
 *
 * @author Juergen Hoeller
 * @since 5.2
 */
public class LogAccessor {

    private final Log log;


    /**
     * Create a new accessor for the given Commons Log.
     *
     * @see LogFactory#getLog(Class)
     * @see LogFactory#getLog(String)
     */
    public LogAccessor(Log log) {
        this.log = log;
    }

    /**
     * Create a new accessor for the specified Commons Log category.
     *
     * @see LogFactory#getLog(Class)
     */
    public LogAccessor(Class<?> logCategory) {
        this.log = LogFactory.getLog(logCategory);
    }

    /**
     * Create a new accessor for the specified Commons Log category.
     *
     * @see LogFactory#getLog(String)
     */
    public LogAccessor(String logCategory) {
        this.log = LogFactory.getLog(logCategory);
    }


    /**
     * Return the target Commons Log.
     */
    public final Log getLog() {
        return this.log;
    }


    // Log level checks

    /**
     * Is fatal logging currently enabled?
     */
    public boolean isFatalEnabled() {
        return this.log.isFatalEnabled();
    }

    /**
     * Is error logging currently enabled?
     */
    public boolean isErrorEnabled() {
        return this.log.isErrorEnabled();
    }

    /**
     * Is warn logging currently enabled?
     */
    public boolean isWarnEnabled() {
        return this.log.isWarnEnabled();
    }

    /**
     * Is info logging currently enabled?
     */
    public boolean isInfoEnabled() {
        return this.log.isInfoEnabled();
    }

    /**
     * Is debug logging currently enabled?
     */
    public boolean isDebugEnabled() {
        return this.log.isDebugEnabled();
    }

    /**
     * Is trace logging currently enabled?
     */
    public boolean isTraceEnabled() {
        return this.log.isTraceEnabled();
    }


    // Plain log methods

    /**
     * Log a message with fatal log level.
     *
     * @param message the message to log
     */
    public void fatal(CharSequence message) {
        this.log.fatal(message);
    }

    /**
     * Log an error with fatal log level.
     *
     * @param cause   the exception to log
     * @param message the message to log
     */
    public void fatal(Throwable cause, CharSequence message) {
        this.log.fatal(message, cause);
    }

    /**
     * Log a message with error log level.
     *
     * @param message the message to log
     */
    public void error(CharSequence message) {
        this.log.error(message);
    }

    /**
     * Log an error with error log level.
     *
     * @param cause   the exception to log
     * @param message the message to log
     */
    public void error(Throwable cause, CharSequence message) {
        this.log.error(message, cause);
    }

    /**
     * Log a message with warn log level.
     *
     * @param message the message to log
     */
    public void warn(CharSequence message) {
        this.log.warn(message);
    }

    /**
     * Log an error with warn log level.
     *
     * @param cause   the exception to log
     * @param message the message to log
     */
    public void warn(Throwable cause, CharSequence message) {
        this.log.warn(message, cause);
    }

    /**
     * Log a message with info log level.
     *
     * @param message the message to log
     */
    public void info(CharSequence message) {
        this.log.info(message);
    }

    /**
     * Log an error with info log level.
     *
     * @param cause   the exception to log
     * @param message the message to log
     */
    public void info(Throwable cause, CharSequence message) {
        this.log.info(message, cause);
    }

    /**
     * Log a message with debug log level.
     *
     * @param message the message to log
     */
    public void debug(CharSequence message) {
        this.log.debug(message);
    }

    /**
     * Log an error with debug log level.
     *
     * @param cause   the exception to log
     * @param message the message to log
     */
    public void debug(Throwable cause, CharSequence message) {
        this.log.debug(message, cause);
    }

    /**
     * Log a message with trace log level.
     *
     * @param message the message to log
     */
    public void trace(CharSequence message) {
        this.log.trace(message);
    }

    /**
     * Log an error with trace log level.
     *
     * @param cause   the exception to log
     * @param message the message to log
     */
    public void trace(Throwable cause, CharSequence message) {
        this.log.trace(message, cause);
    }


    // Supplier-based log methods

    /**
     * Log a message with fatal log level.
     *
     * @param messageSupplier a lazy supplier for the message to log
     */
    public void fatal(Supplier<? extends CharSequence> messageSupplier) {
        if (this.log.isFatalEnabled()) {
            this.log.fatal(LogMessage.of(messageSupplier));
        }
    }

    /**
     * Log an error with fatal log level.
     *
     * @param cause           the exception to log
     * @param messageSupplier a lazy supplier for the message to log
     */
    public void fatal(Throwable cause, Supplier<? extends CharSequence> messageSupplier) {
        if (this.log.isFatalEnabled()) {
            this.log.fatal(LogMessage.of(messageSupplier), cause);
        }
    }

    /**
     * Log a message with error log level.
     *
     * @param messageSupplier a lazy supplier for the message to log
     */
    public void error(Supplier<? extends CharSequence> messageSupplier) {
        if (this.log.isErrorEnabled()) {
            this.log.error(LogMessage.of(messageSupplier));
        }
    }

    /**
     * Log an error with error log level.
     *
     * @param cause           the exception to log
     * @param messageSupplier a lazy supplier for the message to log
     */
    public void error(Throwable cause, Supplier<? extends CharSequence> messageSupplier) {
        if (this.log.isErrorEnabled()) {
            this.log.error(LogMessage.of(messageSupplier), cause);
        }
    }

    /**
     * Log a message with warn log level.
     *
     * @param messageSupplier a lazy supplier for the message to log
     */
    public void warn(Supplier<? extends CharSequence> messageSupplier) {
        if (this.log.isWarnEnabled()) {
            this.log.warn(LogMessage.of(messageSupplier));
        }
    }

    /**
     * Log an error with warn log level.
     *
     * @param cause           the exception to log
     * @param messageSupplier a lazy supplier for the message to log
     */
    public void warn(Throwable cause, Supplier<? extends CharSequence> messageSupplier) {
        if (this.log.isWarnEnabled()) {
            this.log.warn(LogMessage.of(messageSupplier), cause);
        }
    }

    /**
     * Log a message with info log level.
     *
     * @param messageSupplier a lazy supplier for the message to log
     */
    public void info(Supplier<? extends CharSequence> messageSupplier) {
        if (this.log.isInfoEnabled()) {
            this.log.info(LogMessage.of(messageSupplier));
        }
    }

    /**
     * Log an error with info log level.
     *
     * @param cause           the exception to log
     * @param messageSupplier a lazy supplier for the message to log
     */
    public void info(Throwable cause, Supplier<? extends CharSequence> messageSupplier) {
        if (this.log.isInfoEnabled()) {
            this.log.info(LogMessage.of(messageSupplier), cause);
        }
    }

    /**
     * Log a message with debug log level.
     *
     * @param messageSupplier a lazy supplier for the message to log
     */
    public void debug(Supplier<? extends CharSequence> messageSupplier) {
        if (this.log.isDebugEnabled()) {
            this.log.debug(LogMessage.of(messageSupplier));
        }
    }

    /**
     * Log an error with debug log level.
     *
     * @param cause           the exception to log
     * @param messageSupplier a lazy supplier for the message to log
     */
    public void debug(Throwable cause, Supplier<? extends CharSequence> messageSupplier) {
        if (this.log.isDebugEnabled()) {
            this.log.debug(LogMessage.of(messageSupplier), cause);
        }
    }

    /**
     * Log a message with trace log level.
     *
     * @param messageSupplier a lazy supplier for the message to log
     */
    public void trace(Supplier<? extends CharSequence> messageSupplier) {
        if (this.log.isTraceEnabled()) {
            this.log.trace(LogMessage.of(messageSupplier));
        }
    }

    /**
     * Log an error with trace log level.
     *
     * @param cause           the exception to log
     * @param messageSupplier a lazy supplier for the message to log
     */
    public void trace(Throwable cause, Supplier<? extends CharSequence> messageSupplier) {
        if (this.log.isTraceEnabled()) {
            this.log.trace(LogMessage.of(messageSupplier), cause);
        }
    }

}
